TITLE:   GCN CIRCULAR
NUMBER:  37744
SUBJECT: GRB 241002A: NOT optical upper limits
DATE:    24/10/09 07:39:16 GMT
FROM:    Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>

Kasper E. Heintz (DAWN/NBI), Daniele B. Malesani (DAWN/NBI and Radboud Univ.) and Mikael Turkki (NOT and Univ. Helsinki) report on behalf of a larger collaboration:

We observed the field of the Swift GRB 241002A (Caputo et al., GCN 37662), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were affected by strong winds, and the delivered seeing was mediocre (1.6-2"). Observations were carried out with mid times Oct 2.204 and Oct 2.217 UT in the SDSS r and z bands, respectively (4.07 and 4.36 hr after the trigger).

No source is detected consistent with the location of the X-ray afterglow (Osborne et al., GCN 37665), down to limiting magnitudes r > 23.2 and z > 22.5 (both values in the AB system, calibrated against nearby Pan-STARRS point-like sources).